br restore 60k tables failed with error “[domain:8027] Information schema is out of date: schema failed to update in 1 lease, please make sure TiDB can connect to TiKV”

## Bug Report

Please answer these questions before submitting your issue. Thanks!

- TCMS plan: exec plan ID 8203891
- Case: br_restore_batch_create_table_60k (case execution 21114589)
- Testbed: ng-import-into-br-migrate-tps-8203891-1-449, created at 2026-08-29 00:32:46 UTC
- TiDB image: hub-zot.pingcap.net/mirrors/tidbx/pingcap/tidb/images/tidb-server:master-nextgen
- BR image: hub-zot.pingcap.net/mirrors/tidbx/pingcap/tidb/images/br:master-nextgen
- TiKV: 3 replicas, cloud-engine-nextgen; the cluster uses keyspace keyspace_a.

Command:

/br restore full -s s3://nfs/br-backup/br_batch_ddl ... \
-u http://tc-pd.xxx:2379 \
--keyspace-name keyspace_a --check-requirements=false --with-sys-table=false --checksum=true

### 2. What did you expect to see? (Required)

br restore can succeed

### 3. What did you see instead (Required)

The restore started at 2026-08-29 00:56:30 UTC and failed at 01:22:17 UTC with:

[domain:8027] Information schema is out of date: schema failed to update in 1 lease, please make sure TiDB can connect to TiKV

TiDB logs show repeated batched create tables DDL and InfoSchema diff loads immediately before the failure. We did not find TiKV restart, panic, or connectivity errors in the collected logs.

### 4. What is your TiDB version? (Required)
BR release: v26.8.0-65ac2fad58
BR git hash: https://github.com/pingcap/tidb/commit/65ac2fad582510b92d3c4b79999e48217c989737
BR build time: 2026-08-28 20:25:01 UTC
for-next-gen?: true